1. Technical Field
The invention is related to acceleration of internet protocol (IP) data content transfer and load balancing of IP content between Data Over Cable Service (DOCSIS) and MPEG2 Transport (TS) video channels over a Hybrid Fiber Coax (HFC) network and in particular to a system and methods to efficiently and transparently, monitor and process regular IP over DOCSIS and transfer relevant IP data (such as, but not limited to, Television Encoded Media Content, Television Encoded Media Streaming, Programs, Operating System Distribution Images etc . . . ) to end user computing devices (such as, but not limited to, Personal Computer (PC), Set Top Boxes (STB), Over the Top boxes (OTT) or Cable Modem (CM)), during periods where available bandwidth (BW) in the MPEG2 Transport video channels at the HFC infrastructure exists by rerouting & processing the relevant (mainly download) IP flow from the regular low latency and expensive DOCSIS channels direction into the high latency, much more reliable and relatively inexpensive video channels. This is done by encapsulating the content in a video-like transport packets, handle TCP inefficiencies (in case it is TCP—if it isn't then encapsulation is enough) related to high delay video channel by the use of performance enhancing proxy at the sub IP level, send it over video downlink only channels, extract and process the sent content from the video channels at the end user computing device either to be used immediately and taking care of TCP or any other transfer protocol emulation or by using storage if existing in order to cache the content for later demand by the computing device.
2. Related Art
In recent years the internet traffic size has grown exponentially. According to researchers, this growth is mainly attributed to video files either being sent over P2P networks, file downloads, or by direct streaming from Content delivery networks (CDN). It is further expected that the distribution of video content (in either delivery form) will further increase the internet traffic.
P2P traffic, for example, is an “all that you can get” traffic as opposed to bursts of data retrieval and mostly idles connection (http). This fact as well as native large size of video content puts a heavy load on the business model of any broadband operator (such as Cable operator). DOCSIS channels are designed for burst of traffic and not for a steady state traffic flow, as operators resell the same bandwidth to multiple users relying on statistical averaging to accommodate all users' BW requests in the BW limited provided channels. The exponential growth attributed to video traffic is forcing them to upgrade their cable plant with expensive solutions (node splitting, spectrum overlays, more DOCSIS QAM, to name few solutions, DSLAM upgrade, etc.)
Furthermore, in cables Hybrid Fiber Coax (HFC) plant, the network media (implemented as DOCSIS protocol) is shared amongst all users on a service group (SG). Therefore, a steady state, always on, “all that you can get” download service, ruins the statistical effect of uncorrelated networking requests and causes a very negative customer satisfaction especially in the “rush hours” of network capacity (typically at evenings). In addition, it is well known that P2P or other video content tends to be highly repetitive, i.e. several users are downloading the same content. While the media is shared amongst all users on a SG, the connection is individual, i.e. the same content is sent to multiple users on the SG and there is currently no solution for this inefficiency.
One solution for the DOCSIS channels overload is to use Deep Packet Inspection (DPI) in order to reduce the priority and Quality of Service (QoS) of the broadband application services (mainly targeted at P2P traffic). This has the effect of both decreasing the large pool of customer's running P2P application satisfaction on one hand and on the other, promotes ways to hide the P2P services such that DPI becomes irrelevant.
Another solution is to upgrade the cable plant capacity by Spectrum overlay, freeing analog channels, node splitting, etc. Since the video and other large file download applications are using “all you can get”, this solution (although very expensive to implement) provides no real solution to the BW hungry traffic as it quickly fills up the newly available BW again.
While the DOCSIS channels are sharing their BW with all users on a SG, there are many video related services (such as Video on Demand (VOD)) for which channel BW is provisioned but is not used all the time. The BW allocated for those services is a function of the peak usage expected and is indeed used only at small portion of the day time.
Furthermore, a recent technological advance permits assigning channels to switched services (Switched Digital Video (SDV)) and therefore broadcasting and using their BW only when requested to do so by users tuning to these specific services. It is expected that more and more services will transition to switched technology since it offers an opportunity to use the statistics in order to free BW for services that are not required and provide a much greater service offering without actually increasing the HFC capacity. Again, the more switched services, the greater the amount of free BW available at certain hours of the day. In a typical current HFC installation, this amount of free BW sums up to approximately 10 times the amount of BW offered in DOCSIS channels. This factor is expected to grow as the transition to switched services increases. A problem with this available BW, however, is that it exists in video channels and there is currently no connection between DOCSIS channels and video channels.
Another recent technological advance is the use of Docsis Internet Protocol Television Bypass architecture which is using the video channels in order to stream to end-user devices an UDP/IP flow of video.
Another problem with video channel is that it uses a QAM with longer interleaver (in order to provide error free video transmission without retransmission as is implemented in the TCP/IP world). In addition, most common QAMs also use a dejittering and dedrifting buffers which add to the longer latency of the QAM. Typical video QAM latency is in the order of ˜25 msec. Implementing the TCP protocol on these channels greatly reduces the maximal throughput since the server has to wait for a longer delay after transmitting the maximal TCP window in order to get an acknowledgment and continue with the next window of data.
Therefore, what is needed is a system and methods to use the available free BW in non DOCSIS channels (including, but not limited to, VOD channels, MPEG Transport (TS) channels, SDV channels) which are designed by worst case scenario, and use it to transparently redirect IP traffic on a best effort basis and bypassing the Cable Modem Termination System (CMTS). Such a system should require a low cost hardware (as bypassing the CMTS core and reuse of installed based equipment) or software addition to the user computing device in order to transparently catch the bypassed IP traffic and transfer the redirected IP content from the video channels into the computing device. It should also provide substantial increase in download speed for BW intensive content by incorporating an adapted performance enhancement proxy (PEP) while freeing the DOCSIS channel for interactive services such as http. The system should further utilize the fact that most of the content is repetitive, and thus send the content to multiple users and/or CPEs (customer-premises equipment) at once (Multicasting), and even push it to clients it expects will be requesting the content in the future. The system should further not involve a massive upgrade in the HFC plant, but rather an addition of a low cost redirecting server with an interface to the HFC resource managers and switching devices, and of software modifications to tuning devices at the users' premises in order to interface the video channels and capture the IP content sent and redirect it to the end-user computing device as if it came from the regular DOCSIS channels.
In order to solve many operational issues, the above solution should be performed on simple SW upgrade of current CPEs without any additional equipment or connectivity at the end-user premises.